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Cisco Bug: CSCuo56792 - FC interface disabled due to 'bit error rate too high' when rate is low

Last Modified

May 05, 2020

Products (1)

  • Cisco MDS 9000 Series Multilayer Switches

Known Affected Releases

5.2(6b) 6.2(3)

Description (partial)

A Fibre Channel interface is disabled and has the following status even though the bit error rate of the interface is below the threshold specified in the Fibre Channel standards:

  fc1/1 is down (Error disabled - bit error rate too high)

The following type of syslog messages are logged for the interface:

  %PORT-5-IF_DOWN_BIT_ERR_RT_THRES_EXCEEDED: %$VSAN 1%$ Interface fc1/1 is down (Error disabled - bit error rate too high)   
  %MODULE-4-MOD_WARNING: Module 1 (Serial number: JAF1234567) reported warning on ports fc1/1 (Fibre Channel) due to MAC Bit error exceeded threshold in device DEV_TBIRD_MAC (device error 0xc9a01503)

To determine if this bug has been hit, use the following command:
(Where x is the slot or module number and y is the interface or port number.)

slot x show process creditmon event-history

9) Event:CREDITMON_EVENT_ERR_COUNT, length:46, at 446583 usecs after Tue Apr 29 23:20:25 2014
port <y>: cur=0x6ff4 prev=0x6ff3 occurances=15


21) Event:CREDITMON_EVENT_ERR_COUNT, length:46, at 946708 usecs after Sat Apr 26 19:57:48 2014
port <y>: cur=0x6fe7 prev=0x6fe6 occurances=1

If occurances=15 happens after 5 minutes of occurances=1 then this bug has been hit for port fcx/y.
If occurances=15 happens within 5 minutes of occurances=1, then this bug has not been hit.

This issue applies to all FC switching module types.

Related Community Discussions

ISL Trunks errDisabled (bit error rate too high)
Hi All, I have recently completed the installation of ISL links, after the initial configuration they were all ok, until I checked them again this morning and to my surprise I saw the errDisabled error on two links.  Please help me with the resolution of the below errors: fc1/45 20 E on trunking lwcr TE 8 -- fc1/46 20 E on errDisabled lwcr -- -- -- fc1/47 20 E on trunking lwcr TE 8 -- fc1/48 20 E on errDisabled lwcr -- -- -- ------------------------------------------------------------------------------- ...
Latest activity: Jul 17, 2017
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